RPS 1801 - Innovative imaging in colorectal cancer and pelvic floor disorders

Author Block: Q-Y. Li, X-Y. Yan, D. Yang, Z. Guan, R-J. Sun, Q. Lu, L. X. Ting, X. Zhang, Y-S. Sun; Beijing/CN
Purpose: To validate the performance of the ESGAR criteria of nodal status after neoadjuvant therapy (NAT) in rectal cancer and to investigate how morphological features and changes before and after NAT can help with node-by-node pathological comparison.
Methods or Background: Rectal cancer patients who received radical surgery after NAT and had complete pre- and post-NAT MRI were consecutively and prospectively enrolled. For the nodes that achieved node-by-node matched between MRI and pathology, their SADs were measured, and morphological features (i.e. shape, internal structure, and border) were determined on pre- and post-NAT axial T2WI.
Results or Findings: 207 patients were included and 612 nodes achieved matched, including 471 (77.0%) benign and 141 (23.0%) metastatic nodes.
On the post-NAT MRI, the ESGAR criteria, i.e. SAD≥5mm, yield an AUC, sensitivity, and specificity in determining nodal status of 0.67, 52.5%, and 82.4%, respectively. All morphological features differed between benign and metastatic nodes, with AUCs ranging from 0.55 to 0.65. The prediction model combined of the only morphological independent predictor, internal structure, and SAD didn’t result in an improved diagnostic performance compared to SAD alone (P=.64).
As the changes before and after NAT, there were differences in the size reduction rate and the change in internal structure, but not in shape and border. The AUC of the only independent predictor, size reduction rate, was only 0.58.
Conclusion: SAD of 5mm is a feasible criterion for determining nodal status on post-NAT MRI and its diagnostic performance could not be improved by morphological features or changes before and after NAT, which suggests the limited efficacy of conventional features and the urgent need for novel features in the future.
Limitations: The limitation is the lack of histopathological gold standards for every visible node on MRI.
Funding for this study: Funding was received from the National Natural Science Foundation of China (82271955) and Capital's Funds for Health Improvement and Research (2024-1-1022).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the institutional review board (No. 2019KT76).

Author Block: Q-Y. Li, X-Y. Yan, D. Yang, Z. Guan, R-J. Sun, Q. Lu, L. X. Ting, X. Zhang, Y-S. Sun; Beijing/CN
Purpose: To develop a method that enables node-by-node matching between preoperative MRI and postoperative pathology in rectal cancer patients, thereby providing reliable node-based ground-truth labels for further radiological studies.
Methods or Background: This methodological study prospectively enrolled 535 patients (59 ± 11 years; 326 males) with rectal cancer between 2021 and 2023. Target nodes were defined as nodal structures with a short-axis diameter (SAD) of ≥ 3 mm in the mesorectum or around the superior rectal artery on MRI. With relative location to the tumor, rectal wall and mesorectal fascia, each target node was localized in three directions. Combining the coordinates of each node, a 3D node map centered on the tumor and including all target nodes was constructed for each patient and used as a bridge enabling node-by-node matching between MRI and pathology.
Results or Findings: 3,038 target nodes were detected on preoperative MRI, of which 2,220 (73.1%) achieved matched between MRI and pathology.
Of the 1,707 matched benign nodes, 1,321 (77.4%), 378 (22.1%), and 8 (0.5%) had SADs of <5 mm, 5-9 mm and >9 mm, respectively. Whereas of the 513 matched metastatic nodes, 224 (43.7%), 254 (49.5%), and 35 (6.8%) had SADs of <5 mm, 5-9 mm and >9 mm, respectively.
Patients with lower matching rates tended to have higher T-stages and more target nodes on MRI, whereas other factors, e.g. the BMI, therapeutic regimen, tumor location, and time interval between MRI and pathological examination did not show significant effect on the matching accuracy.
Conclusion: A matching method between MRI and pathology was developed to label numerous nodes with precise statuses in rectal cancer patients, which contributes to future radiological studies.
Limitations: The limitation is the small proportion of metastatic nodes compared to benign ones.
Funding for this study: Funding was received from the National Natural Science Foundation of China (82271955) and Capital's Funds for Health Improvement and Research (2024-1-1022).
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: This study was approved by the institutional review board (No. 2019KT76).

Author Block: G. F. Cicala, S. Parisi, F. De Cobelli, V. Burgio, M. Ronzoni, R. Rosati, U. Elmore, P. Passoni; Milan/IT
Purpose: In Locally Advanced Rectal Cancer (LARC), Total Neoadjuvant Therapy (TNT) has shown to be a valid therapeutic option leading to a significant reduction in recurrence, distant metastases, and an improvement in disease-free survival. Magnetic resonance imaging (MRI) plays a crucial role in the detection of extramural venous invasion (EMVI), tumor deposits (TDs), mesorectal fascia invasion (MFI) and helps identify patients who may benefit from a TNT.
Methods or Background: A retrospective analysis was performed on prospectively collected data involving 109 patients who received TNT between 2009 and 2022. MRI scans were conducted both before and after TNT, with a focus on EMVI, TDs, MFI. Following TNT, viable EMVI and TDs were evaluated using a standardized five-point Likert scale.
Results or Findings: Among the 109 patients, 95 patients met the inclusion criteria, 64.2% were male, with a median age of 60.3 years. Positive EMVI scores were observed in 47.4% of cases, while TDs and MFI in 15.7% and 24.7%, respectively. Positive EMVI, TDs, MFI, and Likert scores significantly correlated with reduced time to progression (TTP) and poorer overall survival (OS). In multivariate analysis, the presence of TDs (HR 10.28, p=0.002) and a Likert score of 4 (HR 16.44, p=0.003) were strong independent predictors of shorter TTP.
Conclusion: This study confirms the impact of MRI-detected risk factors as significant predictors of prognosis, supporting the role of a standardized five-point Likert scale in the stratification of patients for personalized treatment.
Limitations: Treatment changes after TNT can lead to false negatives, necessitating a multidisciplinary evaluation for patients. Larger cohorts are needed to improve the Likert scale's reliability.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Pending confirmation from the ethics committee

Author Block: P. N. Franco, C. Maino, C. R. G. L. O. M. Talei Franzesi, R. Corso, D. Ippolito; Monza/IT
Purpose: To assess the performance of Diffusion-Weighted Imaging (DWI) and apparent diffusion coefficient (ADC) values in predicting response to neoadjuvant chemoradiation therapy (CRT) in patients with locally advanced rectal cancer (LARC).
Methods or Background: Ninety-four patients with MRI pre- and post-neoadjuvant treatment were retrospectively enrolled. Three regions of interest (ROIs) were manually drawn on three different tumor slices for every DWI sequence. ROIs were automatically copied to the corresponding ADC maps and the system derived three different ADC values (mean, maximum, and minimum), and the standard deviation (SD). Only mean ADC values were considered. After surgical intervention, pTNM and Mandard tumor-regression-grade (TRG) were obtained. Patients with TRG 1-2 were classified as responders while patients with TRG 3-5 were classified as non-responders.
Results or Findings: No correlation was found between pre-ADC values and TRG classes, while post-ADC and ΔADC values showed a significant correlation with TRG classes (r= -0.285, p=0.002 and r= -0.290, p=0.019, respectively). Post-ADC values were statistically different between responders and non-responders (p=0.019). When considering the relation between overall survival (OS) and ADC values, pre-ADC showed a negative correlation with OS (r= -0.381, p=0.001) while a positive correlation was found between ΔADC values and OS (r= 0.323, p=0.013). According to ΔADC values, the mean OS time between responders and non-responders showed a significant difference (p=0.030). A statistical difference was found between TRG classes and OS (p=0.038) and by dividing patients into responders and non-responders (p=0.019).
Conclusion: The pre-ADC and ΔADC values could be used as useful predictors for patients' prognosis. Post-ADC values, due to their relationship with TRG classes, could be a useful tool to predict response.
Limitations: No correlation between imaging and surgical specimens; the mean interval among CRT, restaging MRI, and surgery was variable among patients.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Upon reviewing the protocol, the local ethical committee deemed formal approval unnecessary, owing to the retrospective, observational, and anonymous nature of this study.

Author Block: T. J. Vogl, A-I. Nica, C. Booz, L. S. Alizadeh, I. Yel, T. Biciusca, A. Gökduman, T. Gruber-Rouh, H. Adwan; Frankfurt/DE
Purpose: To evaluate the efficacy of transarterial chemoperfusion (TACP) and transarterial chemoembolization (TACE) as palliative and symptomatic treatment options for unresectable colorectal carcinoma (CRC) regarding local tumor response and survival.
Methods or Background: Between January 2000 and October 2023, 318 TACP and 80 TACE procedures were performed in 67 patients with locally recurrent or unresectable CRC. Forty-eight patients were treated with TACP (mean 6.2 procedures/patient, range 2-22), 14 with TACE (mean 4.6 procedures/patient, range 2-11) and 5 patients received a combination of both therapies (mean 4.5 procedures/patient, range 2-13). Local tumor response was retrospectively evaluated using the RECIST criteria and overall survival (OS) and progression-free survival (PFS) were calculated using the Kaplan-Meier estimator.
Results or Findings: 49 (73.13%) of the 67 patients had stable disease (SD), 15 (22.39%) progressive disease (PD) and 3 patients (4.48%) partial response (PR). Median OS was 16.17 months, median PFS was 11.25 months. There was no statistically significant difference in OS (P=0.598) and PFS (P=0.847) between patients either receiving TACP or TACE or both treatments. One year after the first procedure, 27 (40.3%) patients were still alive. Nine patients (13.4%) were still alive after 2 years and six patients (8.9%) were still alive after 3 years. No major complications were reported.
Conclusion: CONCLUSION: TACP and TACE are minimally invasive procedures that offer a treatment option for patients with locally recurrent or unresectable CRC, potentially preventing tumor progression and improving quality of life. However, their benefits in the treatment of CRC warrant further investigation.
Limitations: Retrospective, single-center study
Varying follow-up intervals
Short follow-up period
Funding for this study: No funding
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Approval of the ethics committee of the Johann Wolfgang Goethe University, Frankfurt

Author Block: S. Grosu¹, A. Hinterberger², A. E. Sint¹, J. Ricke¹, M. Ingrisch¹, P. Wesp¹; ¹Munich/DE, ²Heidelberg/DE
Purpose: Colorectal cancer (CRC) detection in non-dedicated computed tomography (CT) examinations without bowel preparation is challenging. Current research suggests that liver diseases are associated with an increased risk of colorectal cancer. The aim of this study was to identify patients with CRC using machine learning (ML)-based opportunistic analysis of the liver in non-dedicated routine clinical CT scans.
Methods or Background: Patients 18 years or older with histologically proven CRC or negative colonoscopy that underwent contrast-enhanced CT of the abdomen for various indications within 5 years or less to colonoscopy were included retrospectively. Patients were randomly divided into a training set (75%) and a test set (25%), stratifying for age and sex. Deep learning-based automated liver segmentation on CT images was performed. Standardized Radiomic image features were extracted from the liver segmentations. A random forest ML algorithm was trained on the training set to differentiate between patients with histologically confirmed CRC or negative colonoscopy (non-CRC). Algorithm performance was evaluated on the test set using ROC-AUC, sensitivity and specificity.
Results or Findings: The training set comprised 809 CT scans from 809 patients (mean age = 62.2 years; 42% female), 66 (8 %) with CRC. The test set comprised 270 CT scans from 270 patients (mean age = 62.2 years; 44% female), 23 (9 %) with CRC. The ROC-AUC for random forest-based differentiation between CRC and non-CRC patients was 0.62, with a sensitivity of 74% at a specificity of 50%.
Conclusion: Our results indicate that opportunistic analysis of routine clinical CT images of the liver might have the potential to detect patients with an increased risk for CRC without additional radiation exposure or examinations.
Limitations: Further refinement of the presented model is needed to further increase its diagnostic performance.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ethics committe of the LMU University Hospital, LMU Munich, Munich, Germany

Author Block: T. Lee¹, N. Horvat², M. J. Gollub², J. Garcia-Aguilar², T. H. Kim²; ¹Seoul/KR, ²New York, NY/US
Purpose: To systematically review and meta-analyze the prognostic significance of lateral lymph node metastasis (LLNM) on pretreatment MRI in patients with rectal cancer who undergo neoadjuvant chemoradiation followed by curative surgical resection without lateral lymph node dissection (LLND).
Methods or Background: We searched the MEDLINE and EMBASE databases until September 27, 2023, utilizing the following search terms: (rectal OR rectum OR colorectal) AND (lateral OR sidewall) AND (lymph OR node). The QUIPS tool was employed to evaluate methodological quality. We pooled the association between LLNM on pretreatment MRI and outcomes such as local recurrence, distant metastasis, disease-free survival, and overall survival using hazard ratio (HR) and odds ratio (OR) based on random effects model.
Results or Findings: We included 9 studies, encompassing 3180 patients. LLNM on pretreatment MRI revealed a significant association with increased local recurrence rates (HR: 4.11; 95 % CI: [1.87, 9.02]) and elevated risks for both disease-free (HR: 1.70; 95 % CI: [1.42, 2.03]) and overall survival (HR: 1.76; 95 % CI: [1.44, 2.15]). As for distant metastasis, our analysis indicated a potential trend towards increased rates, though this did not reach statistical significance (HR: 1.67; 95 % CI: [0.85, 3.27]).
Conclusion: Our findings underscore the relationship between LLNM and increased local recurrence and compromised disease-free and overall survival. This emphasizes the potential limitations of relying solely on neoadjuvant chemoradiation and highlights the potential need to intensify treatment in select patients.
Limitations: Firstly, we included a relatively small number of studies. Second, a notable heterogeneity was observed in the criteria used to define LLNM on MRI across different studies, which probably led to heterogenous proportion of LLNM-positive patients among included studies.
Funding for this study: The National Cancer Institute Cancer Center Core Grant P30 CA008748
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: This study was a systematic review and therefore exempt from requiring approval from our institutional review board.

Author Block: G. Sterlicchio, I. Carbone, M. Rengo, C. L. Saletti, D. Bellini; Latina/IT
Purpose: To investigate the diagnostic value and image quality of Open MRI scanner (0.5T) on the evaluation of pelvic floor disfunctions.
Methods or Background: Twenty one patients (20 women and 1 man) underwent MRI defecography using both Open MRI scanner (0.5 T) and high filed MRI scanner (1.5 T). For both scanners, the same MRI protocol has been adopted, including morphological sequences and dynamic sequences during rest and defecation. Contrast-to-noise ratio (CNR), and signal to noise ration (SNR) were calculated and compared among the different data sets. Qualitative assessment of image quality was performed by 3 readers using 5 points Likert scale.
Results or Findings: SNR was significantly lower using 0.5T compared to 1.5T (mean value 33.1 vs 95.2 for T2 sequences and 44.8 vs. 55.6 for dynamic sequences; P<0.05). CNR was significantly lower using 0.5T compared to 1.5T (mean value 37.1 vs 57.6 for T2 sequences and 27.1 vs. 51.3 for dynamic sequences; P<0.05). However, the readers' image quality scores showed that open MRI scanner is not inferior to High magnetic filed. Diagnostic accuracy was the same for both scanners.
Conclusion: Despite the low values of all quantitative quality metrics on 0.5T compared to i.5T, readers perception of image quality is the same between Open MRI scanner and High filed MRI scanner. Low magnetic field does not affect diagnostic accuracy.
Limitations: Small sample size.
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Yes

Author Block: M. Mandolini, V. Carrozzo, A. Calculli, R. Faletti, A. Ferraris; Torino/IT
Purpose: To investigate the association between radiological suspicion of SPFS and the thickness ratio R(PRM/PCM) in patients with pelvic floor disorders.
Methods or Background: The retrospective study involved 109 women (age 17-86 ys, BMI 16-35.5 kg/m2, past pregnancies 76%) who underwent RMI Defecography between November 2021 and September 2024 at our institution. The ESGAR-ESUR recommended protocol was complemented by measurements of PRM and PCM branches thickness made bilaterally at half the length of each bundle and averaged to obtain the ratio R(PRM/PCM).Continuous independent variables were compared with Mann-Whitney’s Test when independent; Wilcoxon’s Test and Bland-Altman plot when correlated; dichotomic variables were studied with Fisher’sTest. PropensityScoreMatching (PSM) was used to reduce the effect of confounding covariates on the outcome.The ReceivingOperatingCurve (ROC) was used to estimate the performance of R with the Area Under The Curve (AUC).
Results or Findings: The 23 (21%) patients satisfying the radiological criteria for SPFS recognized by scientific literature formed the Study Group.PSM extracted from the remaining 84 patients, a Control Group of 23 with baseline comparable (p>0.77, Standardized Mean Difference <0.20) to that of the Study patients. The thickness ratio R was 3.2(3.0-3.5) for the former vs 2.5(2.2-2.75) for the latter (p<0.0001). The ROC curve assessed a good diagnostic ability of R for SPSF, (AUC=0.94) with threshold R≥3.0 (sensitivity 0.87, specificity 0.96, PPV=0.95, NPV=0.88).The measurements made by two readers showed good intra- and inter-operator agreement.
Conclusion: The performance of the PRM/PCM thickness ratio is presently being explored over a larger population; if the positive results will be confirmed, this indicator may become an additional tool for radiological identification of SPFS.
Limitations: The main limitations of the study are the absence of gold standard method for SPFS diagnosis and the small number of our Study Group.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: Being a retrospective preliminary study based on the use of anonymous data, it has not yet been subjected to scrutiny by the ethics committee.